difference of viewport performance between a model with modifiers and modifiers applied #59898

New Issue

Lautaro Iglesias · 2018-12-27T15:38:34+01:00

Lautaro Iglesias commented

2018-12-27 15:38:34 +01:00

System Information
Operating system: Windows 7
Graphics card: Nvidia GTX 1060
Blender Version: 2.80 Beta
Hash: e4dbfe0a98
Date: 2018-12-26

Description:

I have a vehicle model with different parts and modifiers.
When i move the vehicle in the viewport (parented to a box) i get 2 o 3 FPS but if i applied all the modifiers i get 30 FPS despite having the same number of polygons.
In Blender 2.79, i can move the model with modifiers without problem at 30 fps.

Exact steps for others to reproduce the error:
In the attached file you will see both models, one with modifiers and the other one with the modifiers applied. Move the different wire boxes to compare the fps rates. (the file is heavy although i erase some parts, because if i simplified even more, the problem start to disappearing).

Thanks.

system-info.txt Bug_report.blend

System Information Operating system: Windows 7 Graphics card: Nvidia GTX 1060 Blender Version: 2.80 Beta Hash: e4dbfe0a98c1 Date: 2018-12-26 Description: - I have a vehicle model with different parts and modifiers. - When i move the vehicle in the viewport (parented to a box) i get 2 o 3 FPS but if i applied all the modifiers i get 30 FPS despite having the same number of polygons. - In Blender 2.79, i can move the model with modifiers without problem at 30 fps. Exact steps for others to reproduce the error: In the attached file you will see both models, one with modifiers and the other one with the modifiers applied. Move the different wire boxes to compare the fps rates. (the file is heavy although i erase some parts, because if i simplified even more, the problem start to disappearing). Thanks. [system-info.txt](https://archive.blender.org/developer/F6086014/system-info.txt) [Bug_report.blend](https://archive.blender.org/developer/F6086016/Bug_report.blend)

Lautaro Iglesias commented

2018-12-27 15:38:34 +01:00

Added subscriber: @LautaroIglesias

Sebastian Parborg commented

2018-12-28 12:13:26 +01:00

Added subscribers: @Sergey, @ZedDB

Sergey Sharybin was assigned by Sebastian Parborg

2018-12-28 12:13:26 +01:00

Sebastian Parborg commented

2018-12-28 12:13:26 +01:00

@Sergey I think this should be depsgraph related, right? (The finished result should be cached)

But I guess that the performance drop might be related to OpenSubDiv too as the evaluation is slower.

@Sergey I think this should be depsgraph related, right? (The finished result should be cached) But I guess that the performance drop might be related to OpenSubDiv too as the evaluation is slower.

Sergey Sharybin commented

2019-01-04 14:46:26 +01:00

@ZedDB, not sure what you mean by "cache" exactly. In Blender terms it is not supposed to be cached. Is "just" things which are not tagged for update are not supposed to be re-evaluated, and previous evaluation result will be used.

The actual issue here is that such modifier stack is not supposed to be re-evaluated when object transform changes. More slow nature of OpenSubdiv just made the actual issue more obvious.

The root of the issue is the Mirror modifier which says "i do depend on transform of the object", even though actual modifier evaluation does not depend on it unless mirror object is set.

Fix is coming in a bit.

@ZedDB, not sure what you mean by "cache" exactly. In Blender terms it is not supposed to be cached. Is "just" things which are not tagged for update are not supposed to be re-evaluated, and previous evaluation result will be used. The actual issue here is that such modifier stack is not supposed to be re-evaluated when object transform changes. More slow nature of OpenSubdiv just made the actual issue more obvious. The root of the issue is the Mirror modifier which says "i do depend on transform of the object", even though actual modifier evaluation does not depend on it unless mirror object is set. Fix is coming in a bit.

Sergey Sharybin commented

2019-01-04 14:47:07 +01:00

P.S. Forgot to mention, the OpenSubdiv will "cache" topology, so its evaluation will become faster even in more tricky setup.

blender-admin commented

2019-01-04 14:47:16 +01:00

This issue was referenced by e97700ef74

This issue was referenced by e97700ef748617705d3b97487a3193e73692293b

Sergey Sharybin commented

2019-01-04 14:47:50 +01:00

Changed status from 'Open' to: 'Resolved'

Sergey Sharybin closed this issue

2019-01-04 14:47:50 +01:00

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difference of viewport performance between a model with modifiers and modifiers applied #59898